The present invention relates to a method of manufacturing an electrophoretic device, and a method of manufacturing an electronic apparatus, and more specifically, the present invention relates to a method of manufacturing an electrophoretic device facilitating the manufacturing thereof, and a method of manufacturing an electronic apparatus.
A known electrophoretic device is such an electrophoretic display device as shown in FIG. 4, for example. Namely, an electrophoretic microcapsule layer 56 formed by uniformly applying microcapsules 55 in each of which a colored dispersion medium, for example, colored black, and charged white pigment particles dispersed in the dispersion medium are enclosed, is formed between a pair of electrodes 51 and 52. In the case shown in FIG. 4, one of the electrodes is the ITO transparent electrode 52 comprising, for example, an ITO film uniformly formed on one plane of a transparent film 57, and the other electrode comprises a segmented electrode 51 formed by patterning an electrode in segments having an appropriate shape and size. The ITO transparent electrode 52 is at a ground level, and an appropriate dipolar voltage is applied to each of the segments of the segmented electrode 51 to display a desired image.
In this electrophoretic device, for example, the microcapsules 55 containing an electrophoretic dispersion medium are uniformly applied onto the ITO transparent electrode 52 bonded to the transparent film 57, and then the segmented electrode 51 formed on a film 58 is laminated so that the segmented electrode 51 faces the electrophoretic layer 56.
For example, an electrophoretic rewritable sheet having such a structure as shown in FIG. 5 is also known, in which a conductive layer 62 serving as one of the electrodes is formed on a film substrate 61, an application material with microcapsules 63a containing an electrophoretic dispersion medium dispersed therein is applied onto the conductive layer 62 to form an electrophoretic layer 63, and a dielectric coated layer 64 serving as the other electrode is formed on the electrophoretic layer 63. In such an electrophoretic rewritable sheet, by charging the surface of the dielectric coated layer 64, an electric field is applied to the electrophoretic dispersion medium in the microcapsules 63a through the dielectric coated layer 64, so that an image is repeatedly written and deleted.
In a display device having the above-described structure, in order to obtain a good image, the microcapsule layer containing the electrophoretic dispersion medium must comprise a uniform single layer.
However, the microcapsules containing the electrophoretic dispersion medium, which is generally used for electrophoretic display devices, have a large diameter, and cannot be easily uniformly applied in a single layer, and thus a method capable of easily uniformly applying the microcapsule layer is required.
Therefore, the present invention has been achieved in consideration of the above-described unsolved conventional problem, and a first object of the present invention is to provide a method of manufacturing an electrophoretic device capable of easily uniformly applying a microcapsule layer. A second object of the present invention is to provide a method of manufacturing an electronic apparatus comprising an electrophoretic device.
In order to achieve the objects, in a first aspect of the present invention, a method of manufacturing an electrophoretic device that comprises an electrophoretic layer arranged between a pair of electrodes and comprising microcapsules each containing a dispersion medium with electrophoretic particles dispersed therein, comprises the step of attaching the microcapsules to a member while exerting electrical attractive force or electrical repulsive force on the microcapsules to form the electrophoretic layer.
In a second aspect of the present invention, in the above-described method of manufacturing an electrophoretic device, a voltage with polarity opposite to the microcapsules is applied to the member.
In a third aspect of the present invention, in the above-described method of manufacturing an electrophoretic device, the member is one of the pair of electrodes.
In a fourth aspect of the present invention, in the above-described method of manufacturing an electrophoretic device, the member is vibrated in attaching the microcapsules to the member.
In a fifth aspect of the present invention, a method of manufacturing an electrophoretic device comprising an electrophoretic layer that comprises microcapsules each containing a dispersion medium with electrophoretic particles dispersed therein, comprises the step of attaching the microcapsules to a member while exerting electrical attractive force or electrical repulsive force on the microcapsules to form the electrophoretic layer.
In a sixth aspect of the present invention, in the method of manufacturing an electrophoretic device in the fifth aspect, a voltage with polarity opposite to the microcapsules is applied to the member.
In a seventh aspect of the present invention, in the method of manufacturing an electrophoretic device in the fifth or sixth aspect, the member is an electrode.
In an eighth aspect of the present invention, in the method of manufacturing an electrophoretic device in the fifth to seventh aspects, the member is vibrated in attaching the microcapsules to the member.
In the present invention, a method of manufacturing an electronic apparatus comprising an electrophoretic device comprises the step of forming wiring made of a conductive material on a substrate, and the step of manufacturing the electrophoretic device by the above-described method of manufacturing an electrophoretic device.
In the method of manufacturing an electrophoretic device in the first to fourth aspects of the present invention, in attaching the microcapsules, which constitute the electrophoretic layer, to the member to form the electrophoretic layer, electrical attractive force or electrical repulsive force is exerted on the microcapsules. The electrical attractive force or electrical repulsive force can be exerted on the microcapsules by applying, to a member near the microcapsules, for example, a member to which the microcapsules are attached, or the like, a voltage with polarity opposite to or the same as the microcapsules, i.e., a voltage with polarity opposite to or the same as the charge possessed by ones having a higher absolute value of total charge among the electrophoretic particles contained in the microcapsules and the wall films of the microcapsules. For example, when the electrophoretic particles in the microcapsules have positive charge, the wall films of the microcapsules have negative charge, and the electrophoretic particles have a higher absolute value of total charge, and when the electrophoretic layer is formed on, for example, one of the electrodes as the member, the microcapsules are attached to the member in a state a potential with polarity opposite to the charged electrophoretic particles contained in the microcapsules is applied to the electrode. The wall films of the microcapsules and the member, i.e., the electrode, repel each other, while the electrophoretic particles and the electrode attract each other, thereby causing the microcapsules to be attracted to the electrode.
For example, when the microcapsules overlap each other, therefore, the microcapsules in an upper layer are attracted to the electrode to enter the spaces between the respective microcapsules in a lower layer to permit the formation of a uniform single microcapsule layer.
Furthermore, in this case, by vibrating the member vertically or laterally and longitudinally, the microcapsules in the upper layer can easily be moved into the spaces between the microcapsules in the lower layer, and thus the microcapsules can be securely uniformly arranged.
In the method of manufacturing an electrophoretic device in the fifth to eight aspects of the present invention, the same effect as the method of manufacturing an electrophoretic device in the first to fourth aspects of the present invention can be obtained.
The method of manufacturing an electronic apparatus comprises the step of manufacturing an electrophoretic device by the method of manufacturing an electrophoretic device of the present invention, thereby permitting the manufacturing of an electronic apparatus comprising an electrophoretic device having a uniform single microcapsule layer formed therein.